Fair Hades (sic!) (#10718)

adds hair fades ported from polaris

https://github.com/PolarisSS13/Polaris/pull/7313/files

code/modules/mob/abstract/new_player/sprite_accessories.dm

@@ -1712,7 +1712,48 @@ Follow by example and make good judgement based on length which list to include
 			length = 2
 			chatname = "ponytail"
 
+/*
+/////////////////////////////////////
+/  =-----------------------------=  /
+/  == Hair Gradient Definitions ==  /
+/  =-----------------------------=  /
+/////////////////////////////////////
+*/
 
+/datum/sprite_accessory/hair_gradients
+	icon = 'icons/mob/hair_gradients.dmi'
+
+	none
+		name = "None"
+		icon_state = "none"
+
+	fade_up
+		name = "Fade (Up)"
+		icon_state = "fadeup"
+
+	fade_down
+		name = "Fade (Down)"
+		icon_state = "fadedown"
+
+	fade_right
+		name = "Fade (Right)"
+		icon_state = "faderight"
+
+	fade_left
+		name = "Fade (Left)"
+		icon_state = "fadeleft"
+
+	vertical_split_right
+		name = "Vertical Split (Right)"
+		icon_state = "vsplit_right"
+
+	vertical_split_left
+		name = "Vertical Split (Left)"
+		icon_state = "vsplit_left"
+
+	horizontal
+		name = "Horizontal Split"
+		icon_state = "hsplit"
 /*
 ///////////////////////////////////
 /  =---------------------------=  /
@@ -3155,4 +3196,4 @@ Follow by example and make good judgement based on length which list to include
 		xion_lights
 			name = "Xion - Lights Color"
 			icon_state = "xion_lights"
-			body_parts = list(BP_L_LEG,BP_R_LEG,BP_L_ARM,BP_R_ARM,BP_CHEST,BP_HEAD)
+			body_parts = list(BP_L_LEG,BP_R_LEG,BP_L_ARM,BP_R_ARM,BP_CHEST,BP_HEAD)

code/modules/mob/living/carbon/human/human_defines.dm

@@ -5,6 +5,12 @@
 	var/b_hair = 0
 	var/h_style = "Bald"
 
+	//Hair gradient color and style
+	var/r_grad = 0
+	var/g_grad = 0
+	var/b_grad = 0
+	var/g_style = "None"
+
 	//Facial hair colour and style
 	var/r_facial = 0
 	var/g_facial = 0
@@ -116,4 +122,4 @@
 	var/datum/unarmed_attack/default_attack	//default unarmed attack
 
 	var/datum/martial_art/primary_martial_art = null
-	var/list/datum/martial_art/known_martial_arts = null
+	var/list/datum/martial_art/known_martial_arts = null

code/modules/mob/living/carbon/human/species/species.dm

@@ -236,6 +236,7 @@
 
 	var/default_h_style = "Bald"
 	var/default_f_style = "Shaved"
+	var/default_g_style = "None"
 
 	var/list/allowed_citizenships = list(CITIZENSHIP_BIESEL, CITIZENSHIP_SOL, CITIZENSHIP_COALITION, CITIZENSHIP_ELYRA, CITIZENSHIP_ERIDANI, CITIZENSHIP_DOMINIA)
 	var/list/allowed_religions = list(RELIGION_NONE, RELIGION_OTHER, RELIGION_CHRISTIANITY, RELIGION_ISLAM, RELIGION_JUDAISM, RELIGION_HINDU, RELIGION_BUDDHISM, RELIGION_MOROZ, RELIGION_TRINARY, RELIGION_SCARAB, RELIGION_TAOISM)
@@ -607,6 +608,7 @@
 /datum/species/proc/set_default_hair(var/mob/living/carbon/human/H)
 	H.h_style = H.species.default_h_style
 	H.f_style = H.species.default_f_style
+	H.g_style = H.species.default_g_style
 	H.update_hair()
 
 /datum/species/proc/get_species_tally(var/mob/living/carbon/human/H)

code/modules/mob/living/carbon/human/update_icons.dm

@@ -370,7 +370,7 @@ There are several things that need to be remembered:
 // This proc generates & returns an icon representing a human's hair, using a cached icon from SSicon_cache if possible.
 // If `hair_is_visible` is FALSE, only facial hair will be drawn.
 /mob/living/carbon/human/proc/generate_hair_icon(hair_is_visible = TRUE)
-	var/cache_key = "[f_style ? "[f_style][r_facial][g_facial][b_facial]" : "nofacial"]_[(h_style && hair_is_visible) ? "[h_style][r_hair][g_hair][b_hair]" : "nohair"]"
+	var/cache_key = "[f_style ? "[f_style][r_facial][g_facial][b_facial]" : "nofacial"]_[(h_style && hair_is_visible) ? "[h_style][r_hair][g_hair][b_hair]" : "nohair"]_[(g_style && g_style != "None" && hair_is_visible) ? "[g_style][r_grad][g_grad][b_grad]" : "nograd"]"
 
 	var/icon/face_standing = SSicon_cache.human_hair_cache[cache_key]
 	if (!face_standing)	// Not cached, generate it from scratch.
@@ -387,11 +387,19 @@ There are several things that need to be remembered:
 
 		// Hair.
 		if(hair_is_visible)
+			var/icon/grad_s = null
 			var/datum/sprite_accessory/hair_style = hair_styles_list[h_style]
 			if(hair_style && (species.type in hair_style.species_allowed))
 				var/icon/hair_s = new/icon("icon" = hair_style.icon, "icon_state" = hair_style.icon_state)
 				if(hair_style.do_colouration)
+					if(g_style)
+						var/datum/sprite_accessory/gradient_style = hair_gradient_styles_list[g_style]
+						grad_s = new/icon("icon" = gradient_style.icon, "icon_state" = gradient_style.icon_state)
+						grad_s.Blend(hair_s, ICON_AND)
+						grad_s.Blend(rgb(r_grad, g_grad, b_grad), ICON_MULTIPLY)
 					hair_s.Blend(rgb(r_hair, g_hair, b_hair), hair_style.icon_blend_mode)
+					if(!isnull(grad_s))
+						hair_s.Blend(grad_s, ICON_OVERLAY)
 
 				face_standing.Blend(hair_s, ICON_OVERLAY)